Solid insulating compound.



UNITED STATES PATENT OFFICE.

JEROME W. FRANK,

OF NEW YORKLN. Y., AssIeNoR 'ro STANDARD VARNISH WORKS, NEW YORK, N. Y., ACORPORATION or NEW YORK.

SOLID INSULATING COMPOUND.

' tion.

My invention relates to an insulating compound and particularly to an insulating compound capable of use. in insulating transformer coils intended for use immersed in oil.

. The object is to provide a compound hay-- ingggood insulating properties and a high degree of penetration and an added function of retaining its ability to be liquefied after repeated heatings. My invention consists of a solid insulating compound composed of castor oil, a resinous g-uni from a coniferous tree, such, for instance, as colophony, a fossil gum, such for instance, as the New Zealand gum known commercially as gum kauri, or the Dutch,

lliast India copal gums known commercially .a's Manila gum and Pontiniac gum.

.T he several ingredients may be practically combined in the following proportions lOO pounds gum kauri, 25 pounds eolophony, 5 gallons castor oil,

The gum hauri and colophony are first melted and then the east-or oil is added and the mixture boiled until the ingredients are thoroughiv united. After cooling, this compound is ready for use.

The proportions may be varied within reasonable limits to suit special requirements.

In stating the l'ormula I have taken gum kauri, colophony and cast-or oil as samples of the various classes of ingredients which I Specificationof Letters Patent.

Patented Aug. 11, 1908.

Application filed June 28, 1907. Serial No. 381,359.

have mentioned, it being understood that I do not limit myself to the specific ty es mentionedv The material thus formed a ter being liquefied under heat is especially well adapted foijimpregnat-ing in vacuum fabriccovered wires Wound into coils of various forms for the purpose of filling the interstices and insulating saidcoils and providing a filler and coating impervious to mineral oil.

It is an oil resisting insulating filler and covering suitable for insulating transformer coils which operate in a cooling. bath of oil, the colophony serving to revent the compound after'repeated heatings from becoming a pasty mass without penetrating properties and incapable of being liquefied below a temperature in' excess of that which would destroy the fabric covering of the wires in the coils and moreover render the compound valueless'as an insulator and filler for transformer coils.'

What I claim is:'

1. A solid insulating compound composed of castor oil, a fossil gum and a resinous gum from a coniferous-tree combined in the proportions substantially as specificd.

2. A solid insulating compound composed of castor oil, gum'kauri and eolophoirv (011)- bined in the proportions substantiallr as specified.

In testimony, that I claim the foregoing as my invention, I have signed my name in resence of two witnesses, this 22nd da ol iiune, 1907.

. JEROME W. FRANK.

IYitnesss:

W. H. S'rnT'r, R. CmssoN. 

